In accordance with EPA regulations, a storm water permit may be required for discharge of storm water. Evidence of compliance with this requirement shall be provided.
Drainage laterals which include an adequate outlet shall be designed and constructed to provide for disposal of all surface water. Such design shall accommodate a five (5)-year frequency storm with the sewer pipe flowing full and a ten (10)-year frequency hydraulic grade line below the pavement low point. The drainage system shall, in addition, provide a drainage outlet a minimum of three (3) feet below the mean ground level for each lot. Drainage ditches shall be enclosed to accommodate the estimated ten (10)-year storm when the enclosure is equivalent in capacity to 48 inches in diameter or less. Such enclosures shall be constructed, installed and paid for by the subdivider. All ditches shall be enclosed within the new street right-of-way. Such enclosures shall be adequate to handle the storm drainage and shall be constructed, installed and paid for by the subdivider. Copies of calculations illustrating estimated volumes and peak flows of runoff shall be provided for review by the Village Engineer.
Detention of storm water runoff on-site may be required if, in the opinion of the Village Engineer, such detention is required to prevent down stream flooding.
Where flood plains are being reduced or eliminated by the site grading of the proposed subdivision, approval shall be obtained from the applicable agency as to the water course's adequacy to handle the additional water due to the altered land use collections. The 100-year flood plain elevation shall be shown on the preliminary drawing as well as on the final plat. The lowest finished floor elevations shall be a minimum of one foot above the regulatory 100-year flood plain. (Ord. 574. Passed 5-21-97.)